Explanation/Reference:
Explanation:
VMware vCenter is
optional when deploying on UC on UCS Tested Reference Configuration hardware

mandatory when deploying on UC on UCS Specs-based and Third-party Server Specs-based

hardware.
vCenter Statistics Level 4 logging is mandatory so that Cisco TAC is able to provide effective support.

Click here for how to configure VMware vCenter to capture these logs. If not configured by default,

Cisco TAC may request enabling these settings in order to provide effective support.
Also note that enablement of specific VMware vSphere management features may require vCenter

and/or a higher feature Edition of vSphere ESXi.
Cisco Collaboration does not require its own dedicated vCenter.

Note that when VMware vCenter is not required and is not used, then VMware vSphere ESXi's default

management interface is its free/included VMware vSphere Client (formerly branded VI Client).
Reference: http://docwiki.cisco.com/wiki/Unified_Communications_VMware_Requirements